The invention relates to a method and apparatus producing a selvage on fabrics and more particularly to a method and apparatus for producing a selvage on fabric produced on looms which utilize bobbinless filling insertion members.
Heretofore, in forming a selvage on a fabric produced on a loom wherein a bobbinless filling inserting member such as projectiles, grippers, liquid streams or the like are utilized, the ends of the filling threads are turned one hundred and eighty degrees and reinserted in the shed subsequent to the beat-up of the next thread. These filling threads may be in the form of a single pick or loop.
The formation of a selvage on a fabric produced in the above described manner is a problem on account of it produces a greater fabric density in the region of the selvage. This is because in forming the selvage, the filling thread as well as the reinserted filling thread end are respectively bound by the warp threads. In one attempt to minimize this problem, weaving is performed with a looser weave for the edge region in which the selvage is to be formed as compared to the rest of the fabric. This requires additional mechanisms with the complication of necessary additional shafts and their drive which occasion considerable cost.
To prevent an excessive fabric density in the region of the selvage, it has already been proposed U.S. Pat. No. 3,457,966 to insert only every other filling thread into the shed and to leave the rest of the thread ends as an unbound edge fringe. This has the disadvantage in that the fringe must either be removed in an additional work step or by a special device on the loom.